Work is continuing to clear the railway line south of Kaikoura, after a landslide derailed a northbound freight train Monday night.
KiwiRail said it hoped to have the line open late today or early tomorrow.
Rail services between Picton and Christchurch would resume as soon as the line was clear, the company said.
Two locomotives and several wagons derailed when the 30-wagon freight train hit the slip between Claverley and Oaro around 11pm on Monday.
The driver of the locomotive suffered minor injuries, and was treated at a local medical centre, before being discharged early yesterday.
A KiwiRail spokeswoman said cranes were on site and some of the wagons were back on the tracks.
"We hope to have the line reopened later today or early tomorrow," she said.